In the past, there have been proposed various lighting devices including light-emitting diode (LED) feeding devices. For example, JP 2012-244737 A discloses an LED feeding device configured to turn on an LED (light source) with power supplied from an AC power supply (power supply). The LED feeding device of JP 2012-244737 A includes an output power adjusting circuit (step-down chopper circuit) including a switch device and operating to extract desired power for the LED, and a driving circuit to drive the switch device. Further, the LED feeding device of JP 2012-244737 A includes a stop control circuit to determine whether the LED is present or absent based on detection of a current flowing through the LED and to stop the drive circuit when determining that the LED is absent.
The LED feeding device of JP 2012-244737 A may have a probability that the switch device (step-down switching device) of the step-down chopper circuit is short circuited. If the step-down switching device is short circuited, the voltage of the AC power supply may be applied across the LED and this may cause an excess current to flow through the LED. The LED feeding device of JP 2012-244737 A can determine whether the LED is present or absent, but cannot detect short circuit of the step-down switching device.